1. Field
The disclosure relates to a supporter for a fuel cell, and an electrode, a membrane-electrode assembly, and a fuel cell system including the same.
2. Description of the Related Technology
A fuel cell is a power generation system for producing electrical energy through a chemical reaction between an oxidant and hydrogen from a hydrocarbon-based material such as methanol, ethanol, or natural gas. Such a fuel cell is a clean energy source with the potential to replace fossil fuels.
Fuel cells include a stack composed of unit cells, each configured to produce various ranges of power. Since a fuel cell has about four to ten times higher energy density than a small lithium battery, it has been highlighted as a small portable power source.
Typical examples of fuel cells include polymer electrolyte membrane fuel cells (PEMFC) and direct oxidation fuel cells (DOFC). A direct oxidation fuel cell that uses methanol as a fuel is called a direct methanol fuel cell (DMFC). The PEMFC has an advantage of high energy density and high power, and a DOFC has lower energy density than that of the polymer electrolyte fuel cell, but it has the advantages of easy handling of a fuel, being capable of operating at room temperature due to its low operation temperature, and no need for additional fuel reforming processors.
In the above-mentioned fuel cell systems, the stack that generates electricity includes several to scores of unit cells stacked adjacent to one another. Each unit cell is formed from a membrane-electrode assembly (MEA) and a separator (also referred to as a bipolar plate). The MEA is composed of an anode (also referred to as a “fuel electrode” or an “oxidation electrode”) and a cathode (also referred to as an “air electrode” or a “reduction electrode”) separated by a polymer electrolyte membrane. Fuel is supplied to the anode and adsorbed on catalysts of the anode. The fuel is oxidized to produce protons and electrons. The electrons are transferred into the cathode via an external circuit, and the protons are transferred into the cathode through the polymer electrolyte membrane. In addition, an oxidant is supplied to the cathode, and then the oxidant, protons, and electrons react on catalysts of the cathode to produce both electricity and water.